U.S. patent number 4,493,573 [Application Number 06/476,222] was granted by the patent office on 1985-01-15 for printing apparatus.
This patent grant is currently assigned to Ricoh Company, Ltd.. Invention is credited to Masanori Hashimoto, Shunichi Ogawa.
United States Patent |
4,493,573 |
Hashimoto , et al. |
January 15, 1985 |
Printing apparatus
Abstract
A printing apparatus including a printing sheet guide for
supporting a single printing sheet, a page feeder for successively
feeding a plurality of continuous sheets to a printing section, and
a sound absorber and a noise silencing cover for avoiding release
of noise to outside. The printing apparatus has a front cover
located forwardly of an upper cover for a printer body for movement
between an open position and a closed position, and a pair of
brackets are inserted in engaging holes formed on opposite sides of
the upper cover. The printing sheet guide and the noise silencing
cover are detachably attached to the brackets, and the page feeder
includes engaging portions located on opposite sides which are
inserted in positions at the front cover outwardly of the sound
absorber and the noise silencing cover and inwardly of hinged
portions on opposite sides of the front cover to be releasably
brought into engagement with a platen shaft. The front cover is
brought to an open position without removing any of the optionally
mounted components.
Inventors: |
Hashimoto; Masanori (Yokohama,
JP), Ogawa; Shunichi (Hatano, JP) |
Assignee: |
Ricoh Company, Ltd.
(JP)
|
Family
ID: |
26381499 |
Appl.
No.: |
06/476,222 |
Filed: |
March 17, 1983 |
Foreign Application Priority Data
|
|
|
|
|
Mar 19, 1982 [JP] |
|
|
57-42831 |
Mar 26, 1982 [JP] |
|
|
57-41841 |
|
Current U.S.
Class: |
400/647.1;
400/690.1; 400/690.4; 400/692 |
Current CPC
Class: |
B41J
29/10 (20130101); B41J 13/14 (20130101) |
Current International
Class: |
B41J
13/14 (20060101); B41J 29/10 (20060101); B41J
013/14 (); B41J 029/10 () |
Field of
Search: |
;400/690.4,689,690,690.1,690.2,690.3,692,693,605,647.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
IBM Technical Disclosure Bulletin vol. 24, No. 8, Jan. 1982, p.
4101, "Acoustic Cover" by Meister, Jr..
|
Primary Examiner: Sewell; Paul T.
Assistant Examiner: Pearson; Charles A.
Attorney, Agent or Firm: Shoup; Guy W.
Claims
What is claimed is:
1. A printing apparatus comprising:
a printer body;
an upper cover secured to said printer body;
a front cover attached to the printer body by hinged portions on
opposite sides of the front cover in a position forwardly of said
upper cover and movable between an open position and closed
position;
a platen interposed between said upper cover and said front
cover;
means to selectively mount one or more of a group of components
including a sound absorber, a printing sheet guide, a noise
silencing cover and a page feeder;
a pair of brackets each removably inserted in one of two engaging
holes formed on opposite sides of said upper cover, each of said
brackets having a first engaging portion located on an inner side
of said bracket and a second engaging portion located on an outer
side of said bracket;
said sound absorber detachably inserted along said platen;
said printing sheet guide releasably brought into engagement at
corners on opposite sides with said first engaging portions of said
brackets so that the printing sheet guide can be set in a
predetermined position or brought to a lying position when not in
use;
said noise silencing cover releasably brought into engagement at
forward ends of arms located on opposite sides of said noise
silencing cover with said second engaging portions of said brackets
to thereby cover a printing section in a manner to be freely opened
and closed; and
said page feeder including engaging portions located on opposite
sides of said page feeder which are inserted in positions at the
front cover outwardly of the sound absorber and the noise silencing
cover and inwardly of said hinged portions in such a manner that
said engaging portions are releasably brought into engagment with a
shaft of said platen;
wherein said components to be optionally mounted on the printing
apparatus can be mounted either singly or plurally in any
arbitrarily selected combination as desired, and the front cover
can be brought to an open position without removing the optionally
mounted component or components for replacing a ribbon or a
printing wheel with a new one.
2. A printing apparatus as claimed in claim 1, further comprising a
pair of blind plates each detachably attached in one of said
positions at said front cover in which one of said engaging
portions is inserted, said blind plates being removed from their
positions when the page feeder is mounted on the printing
apparatus.
3. A printing apparatus as claimed in claim 1, wherein said page
feeder includes side covers each formed with a locking claw having
resilience and projecting in angled form from the surface of the
side cover, said locking claws being brought into locking
engagement with inner side edges of said front cover when the front
cover is brought to an open position.
4. A printing apparatus as claimed in claim 1, further comprising a
printing section located in the printer body and supported on a
carriage, a pair of wire pulleys for driving the carriage supported
by a frame, and a pair of covers detachably attached to said frame
to close openings for the wire pulleys to slightly extend upwardly
therethrough.
Description
BACKGROUND OF THE INVENTION
This invention relates to a printing apparatus, and more
particularly it is concerned with improvements in or relating to an
optional components mounting mechanism of a printing apparatus.
Generally, a printing apparatus has components that are optionally
mounted, such as a printing sheet guide for supporting a single
sheet that is inserted, a page feeder for successively feeding a
set of sheets arranged continuously, etc. In a printing apparatus
of the type generally referred to as an impact printer wherein
printing types are struck with a hammer when printing is performed,
a sound absorber or a noise silencing cover may optionally be
mounted for avoiding making a noise.
Printing apparatus of the prior art have suffered, however, the
disadvantage that if at least one of the sound absorber, noise
silencing cover and printing sheet guide is mounted, then it is
impossible to mount the page feeder. When it is necessary to mount
the page feeder, it is necessary to dismount the sound absorber,
noise silencing cover and printing sheet guide, and this is
troublesome and makes one wonder where the removed components
should be placed. To avoid this trouble, attempts have been made to
produce two types of printing apparatus, one type being adapted to
mount the sound absorber, noise silencing cover and printing sheet
guide and the other type being intended to mount the page feeder.
Also, some printing apparatus have had the page feeder and the
noise silencing cover attached thereto, which became so large in
size that separate printing apparatus have been produced merely for
mounting the printing sheet guide. In the type of printing
apparatus mounting the page feeder, one has to remove the noise
silencing cover and a front cover of the printing apparatus when
the ribbon and printing wheels are replaced by new ones, and one
has to remove the page feeder each time the ribbon and printing
wheel are replaced by new ones, depending on the type of printing
apparatus. Opening and closing the noise silencing cover and front
cover have tended to cause abnormal conditions to be produced in
the printing apparatus in which the sheet in the process of setting
might be folded or wound on the platen, making it inevitable to
reinsert the sheet into the printing apparatus.
Printing apparatus adapted to mount optionally the page feeder for
feeding into the printing section sheets arranged continuously in a
set might be constructed such that when the page feeder is mounted,
left and right side frames of the page feeder penetrate a printer
cover and are brought into engagement with engaging portions in the
interior. When this type of printing apparatus has no page feeder
mounted thereon, the page feeder mounting portions (portions where
the frames penetrate the printer cover) of the printer cover would
be left open to allow the engaging portions and gears in the
interior to be exposed to view. When this is the case, the operator
might be tempted to put fingers into the openings or the fingers
might actually be injured by mistake. In the impact type printing
apparatus, sound is produced each time printing is performed, so
that it is usual practice to cover the printing section with the
sound absorber or noise silencing cover to avoid release of noise
to the outside. However, noise might be emitted through the
openings of the page feeder mounting portion unless the openings
are closed.
SUMMARY OF THE INVENTION
This invention has been developed for the purpose of obviating the
aforesaid disadvantages of the prior art. Accordingly the invention
has, as one of its objects, the provision of a printing apparatus
capable of mounting a page feeder irrespective of whether or not a
sound absorber, a noise silencing cover and a printing sheet guide
are already mounted. The invention allows the front cover, when all
the aforesaid components have all been mounted, to be opened to
replace the ribbon and/or the printing wheel set in the printing
apparatus, without requiring removal of the optional components
already mounted.
Another object is to provide a printing apparatus including blind
plates detachably attached to the page feeder mounting portions of
a front cover, the blind cover being left in place when no page
feeder is mounted and removed from its position when the page
feeder is mounted.
To accomplish the aforesaid first object, there is provided
according to the invention a printing apparatus comprising an upper
cover secured to a printer body, a front cover detachably attached
to the printer body in a position forwardly of the upper cover in
such a manner that it can be freely opened and closed, and a platen
interposed between the upper cover and the front cover. The
printing apparatus is adapted to optionally mount a pair of
brackets, sound absorber, a printing sheet guide, a noise silencing
cover and a page feeder. The pair of brackets are each removably
inserted in one of two engaging holes formed on opposite sides of
the upper cover. The sound absorber is detachably inserted along
the platen. The printing sheet guide releasably brought into
engagement at corners on opposite sides with first engaging
portions of the brackets located on inner sides thereof so that the
printing sheet guide can be set in a predetermined position or
brought to a lying position when not in use. The noise silencing
cover is releasably brought into engagement at forward ends of arms
located on opposite sides with second engaging portions of the
brackets located on outer sides thereof to thereby cover a printing
section in a manner to be freely opened and closed. The page feeder
includes engaging portions located on opposite sides which are
inserted in positions at the front cover outwardly of the sound
absorber and the noise silencing cover and inwardly of hinged
portions on opposite sides of the front cover in such a manner that
they are releasably brought into engagement with a shaft of the
platen. The components optionally mounted on the printing apparatus
can be mounted either singly or plurally in any arbitrarily
selected combination as desired and the front cover can be opened
without removing the optionally mounted component or components for
replacing a ribbon or a printing wheel with a new one.
To accomplish the aforesaid second object, there is provided
according to the invention a printing apparatus comprising a pair
of blind plates each detachably attached to one of two page feeder
mounting portions of the front cover in such a manner that they can
be removed when the page feeder is mounted.
Additional and other objects, features and advantages of the
invention will become apparent from the description set forth
hereinafter when considered in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the printing apparatus comprising
one embodiment of the invention, having no component optionally
mounted thereon;
FIG. 2 is a perspective view of the printing apparatus shown in
FIG. 1, having a sound absorber and brackets attached thereto;
FIG. 3 is a perspective view of the printing apparatus shown in
FIG. 2, having a printing sheet guide and a noise silencing cover
mounted thereon;
FIG. 4 is a perspective view of the printing apparatus shown in
FIG. 3, having a page feeder mounted thereon;
FIG. 5 is a view of the printing apparatus shown in FIG. 4, showing
the apparatus mounting the optional components and having the front
cover moved to an open position;
FIG. 6 is perspective view of the sound absorber, showing its
construction;
FIG. 7 is a perspective view of the bracket, showing its
construction;
FIG. 8 is a view showing the construction of the extension guide
and the mounting mechanism therefor;
FIG. 9 is a view of the construction of the noise silencing
cover;
FIGS. 10 and 11 are perspective views of the internal mechanism
arranged below the front cover;
FIG. 12 is a perspective view of the page feeder;
FIG. 13 is a view showing the construction of the principal
portions of the page feeder;
FIG. 14 shows the page feeder shown in FIG. 12, shown in another
condition of use;
FIG. 15 is a view of the construction of the page feeder in
engagement with the platen shaft;
FIG. 16 is a view of the blind plates attachable to the front
cover;
FIG. 17 is a perspective view of the carriage section of the
printing apparatus;
FIG. 18 is a plan view showing the condition in which the wire for
moving the carriage is mounted;
FIG. 19 is a front view showing the carriage moving wire;
FIGS. 20 and 21 are perspective views, on an enlarged scale, of the
cover for the wire pulleys, viewed from different directions;
and
FIG. 22 is a sectional view of the essential portions showing the
condition in which the covers for the wire pulleys is mounted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention will now be described by referring to
the accompanying drawings. Referring to FIG. 1, there is shown an
impact printing apparatus according to the invention which has no
optional components mounted thereon. The impact printing apparatus
comprises an upper cover 1 secured to a printer body and formed of
grafted polyphenylene ether resin, a front cover 2 formed of the
same material as the upper cover attached to the printer body in a
position forwardly of the upper cover 1 in such a manner that the
front cover 2 can be freely opened and closed, and a platen 3
interposed between the upper cover 1 and the front cover 2. A
printing sheet 4 is inserted in the direction of an arrow and set
in position by turning a knob 5. In the case of a printing
apparatus, printing is usually started at the start position at the
left end portion of the sheet regardless of its size. The numeral 6
designates a bail shaft for keeping the printing sheet 4 down, and
the numeral 7 designates a character scale.
FIG. 2 shows the impact printing apparatus shown in FIG. 1, which
further mounts a sound absorber 8 detachably attached along the
platen 3, and the pair of brackets 10 each removably inserted in
one of engaging holes 9 (see FIG. 1) formed on opposite sides or
left and right sides of the upper cover 1.
The sound absorber 8 made as of an ABS resin is formed, as shown in
FIG. 6, at opposite ends thereof with receiving openings 21 of a
shape of an inverted letter U which are adapted to have snugly
fitted therein projections formed on the printer body by utilizing
the resilience of the material, to thereby attach the sound
absorber 8 in place. The sound absorber 8 is also formed in upper
portions of its opposite sides with knurled surfaces 22 that can be
gripped by the operator to pull the sound absorber 8 out of
engagement with the printer body to remove same, and has a sound
absorbing material 23, such as polyester foam, stuffed in its
interior. When the sound absorber 8 is in its position on the
printer body, the sound absorber 8 is preferably held in position
while one end portion thereof is in contact with the platen 3 to
facilitate absorbing sound and inserting a printing sheet. To this
end, a weight 24 is secured to the sound absorber 8 to allow a
moment of rotation oriented in the direction of an arrow to be
produced at all times with respect to its support axis.
The brackets 10 made as of a polyacetal resin are each formed, as
shown in FIG. 7, with a pair of resilient claws 25 located on
opposite sides or front and rear sides and are adapted to be snugly
fitted in one of the engaging holes 9 formed in the upper cover 1
to be secured in place on the printer body and readily removed if
so desired. Each bracket 10 is formed on opposite sides with
engaging pins 26a and 26b with which a printing sheet guide and a
noise silencing cover are brought into engagement, to be thereby
held in place.
FIG. 3 shows the printing apparatus shown in FIG. 2 which further
mounts the printing sheet guide 11 for guiding the insertion of a
copying sheet and the noise silencing cover 12. The printing sheet
guide 11 is formed in corners at opposite ends with engaging
openings which are partly cut out and are adapted to receive
therein the inner engaging pins 26a of the brackets 10, to attach
the guide 11 to the printer body. The noise silencing cover 12 is
formed at forward ends of arms 12a on opposite sides with engaging
openings which receive, by utilizing the resilience of the arms
12a, the outer engaging pins 26b of the brackets 10, to attach the
upper cover 1 to the printer body. Thus the printing sheet guide 11
and noise silencing cover 12 can be releasably brought into
engagement with the brackets 10 fitted on opposite sides of the
upper cover 1 and can be pivoted about the engaging portions of the
brackets 10. The noise silencing cover 12 is transparent and
cooperates with the sound absorber 8 to provide a shield to a
printing section of the apparatus to avoid noise being released to
the outside. The printing sheet guide 11 has attached to its back
folding legs, not shown, which are set at an optimum angle for
inserting a printing sheet and can be brought to a lying position
when not in use. The numeral 27 in FIG. 7 designates a stopper for
holding the noise silencing cover 12 when the latter is lifted and
bent toward the printing sheet guide 11.
The printing sheet guide 11 will be described further in detail.
The guide 11 includes an extension guide 13 formed as of an ABS
resin which can be telescopically extended when necessary. As shown
in FIG. 8, the extension guide 13 is formed with two rows of angled
projections 30 at its bottom surface and grooves 31 on opposite
side surfaces. When the extension guide 13 is inserted in the
printing sheet guide 11 by fitting projections 32 on the guide 11
in the grooves 31, the angled projections 30 can be brought into
engagement with a resilient pawl 33 formed on the printing sheet
guide 11 to enable the extension guide 13 to be held in any
extended position as desired. When the extension guide 13 is
withdrawn from the guide 11 to its outermost position, another
resilient pawl 34 is brought into engagement with a final offset
portion 35 of the extension guide 13 to prevent the extension guide
13 from being released from engagement with the printing sheet
guide 11. When the extension guide 13 is inserted in the guide 11
to its innermost position, a portion of the former underlies the
bottom surface of the latter and is hidden from the view. The
numeral 14 in FIG. 3 designates a slidable positioning guide for
regulating the position of an end portion of a printing sheet to be
set in position.
The noise silencing cover 12 made as of an AS resin is transparent
to show the interior, and formed, as shown in FIG. 9, with grooves
in portions thereof coming into contact with the front cover 2 of
the printing apparatus which surround the cover 12 on three sides
thereof and have fitted therein a filler 36 formed as of rubber
having noise silencing and vibration damping effects. FIG. 9(B)
shows in a cross section taken along the line X--X the noise
silencing cover 12 shown in FIG. 12(A) which has a character scale
37 printed on a surface thereof juxtaposed against the sound
absorber 8. Thus the platen 3 is covered at its top with the sound
absorber 8 and noise silencing cover 12 so that the noise produced
when printing is performed can be kept from being released to the
outside.
FIG. 4 shows the impact printing apparatus shown in FIG. 3, shown
with a page feeder 15 additionally mounted thereon. In this case,
the printing sheet guide 11 is brought to a lying position by
folding the legs, and blind plates 16 detachably attached to
portions of the front cover 2 located outwardly of the sound
absorber 8 and the arms 12a of the noise silencing cover 12 (see
FIGS. 2 and 3) are detached (they can be readily removed upon
opening the front cover 2 in the condition shown in FIG. 3) to
enable engaging portions 59a of side covers 59 of the page feeder
15 to be inserted therein into engagement with a shaft of the
platen 3.
The page feeder 15 includes tractors 57 for successively feeding
sheets arranged continuously one after another as shown in FIG. 12.
The side covers 59 have engaging portions at their forward ends
which are inserted into the printer body in positions located at
the front cover 2 outwardly of the tractors 57 and inwardly of
hinged portions 2a of the front cover 2, to be brought into
engagement with the shaft of the platen 3. The tractors 57 are
driven through a transmission gearing in meshing engagement with a
drive gear secured to the shaft of the platen 3. Portions of the
side covers 59 inserted through the front cover 2 into the printer
body have a relatively small thickness, so that it is possible to
reduce the external dimensions of the printing apparatus without
reducing the width thereof available for printing. The side covers
59 are each formed in a portion thereof above the portion inserted
into the printer body with a locking claw 41 having resilience. The
locking claws 41 are each formed, as shown in FIG. 13, when one of
the side covers 59 are made of resin, in the shape of a strip
surrounded on three sides by cuts 58 and bent in wave form in cross
section. The locking claws 41 can make use of the resilience of the
resin by virtue of the cuts made on three sides of the strip. The
locking claws 41 are formed on the side covers 59 on the opposite
sides of the page feeder 15. FIG. 13(A) is a sectional view taken
along the line X--X in FIG. 13(B).
When it is desired to replace the ribbon or the printing wheel by a
new one in the embodiment of the invention having the optional
components mounted thereon, the front cover 2 can be brought to an
open position by the operator gripping knurled portions 42 formed
on opposite sides of the cover 2, as shown in FIG. 14. At this
time, inner side edges of the front cover 2 move past the locking
claws 41 formed on the side covers 59 of the page feeder 15 and
engaged thereby, so that the front cover 2 catches against the
locking claws 41 and is held and locked thereby even if the hands
of the operator are removed from the knurled portions 42. The
locking claws 41 are flexed when the inner side edges of the front
cover 2 move past them but restored to their original positions by
their resilience. When it is desired to bring the front cover 2 to
a closed position, the operator has only to push the front cover 2
lightly downwardly. This causes the engaging claws 41 to flex,
thereby allowing the front cover 2 to move downwardly.
When the page feeder 15 is mounted on the printer body, a drive
gear 52 secured to a shaft 51 of the platen 3 has a support ring 53
loosely fitted over a shaft portion 52a of the drive gear 52, and a
forward end portion of a frame 54 of the page feeder 15 is in
engagement with the support ring 53 and latched by a latch lever
55. At this time, a gear 56 on the frame 54 meshes with the drive
gear 52, so that motive force is transmitted from the drive gear 52
to the page feeder 15 through the series of gears described
hereinabove. When the page feeder 15 is not mounted, the blind
plates 16 are fitted in the openings at the front cover 2. When
these openings for the engaging portions are open at all times,
noise may leak therethrough and the interior of the printer is
undesireably exposed.
From the foregoing description, it will be appreciated that
according to the invention the page feeder 15 can be mounted on the
impact printing apparatus while the sound absorber 8, printing
sheet guide 11 and noise silencing cover 12 are already mounted (or
without these components mounted), and that the front cover 2 can
be opened, as shown in FIG. 5, without removing the optionally
mounted components. Moreover, when the front cover 2 is opened, it
can be locked in place by bringing it into engagement with the
locking claws 41 located in positions on the side covers 59 of the
page feeder 15 above the engaging portions 59a.
It is necessary to open the front cover 2 when the printing wheel
and the ribbon are replaced by new ones or a switch or a key is
actuated. When it is brought to a closed position, it is locked in
position as locking claws 43, having resilience and formed
integrally with the upper cover 1 on an inner side of a front bar
1a of the upper cover 1 as shown in FIG. 5, are brought into
engagement with square openings 44 formed at the front cover 2 in
positions corresponding to the positions of the locking claws 43 as
shown in FIGS. 10 and 11. The locking claws 43 do not stick out of
the cover and there are no risks of the fingers being caught
thereby. The provision of a rubber member in the vicinity of the
locking claw 43 prevents noise from being made by friction between
the covers due to vibration and gives a fine feel to the operator
when the front cover 2 is locked in position.
When the front cover 2 is brought to an open position, a printing
section supported by a carriage is revealed, as shown in FIG. 10.
The printing section has a printing hammer 46 juxtaposed against
the platen 3, a printing wheel, not shown, attached to a front
surface of the printing hammer 46 and a ribbon cassette 47 mounted
on the printing hammer 46. The upper cover 1 includes an inner edge
portion 1b formed to conform to the external shape of the ribbon
cassette 47 when the printing section is in its starting position.
This makes the apparatus look neat and stable. The printing section
further has located at one side an operation lever 48 and a switch
49 for regulating the spacing between the platen 3 and printing
hammer 46 depending on the thickness of printing sheets as shown in
FIG. 11. Mechanical portions actuated by the lever 48 and switch 49
are enclosed by a cover 50 formed unitary with the upper cover 1,
to separate the mechanical portions from the other portions.
From the foregoing description, it will be appreciated that the
invention enables optionally mounted components including the
printing sheet guide, sound absorber, noise silencing cover and
page feeder to be mounted on a printing apparatus all at once or in
any combination as desired. Moreover, these components can be
mounted or removed quite readily in one operation. Thus regardless
of whether the printing sheet guide and page feeder are mounted,
release of noise to the outside can be avoided by mounting the
sound absorber and noise silencing cover so that the apparatus
makes little noise. Since the front cover can be opened and closed
without requiring removal of the optional components, it is
possible to carry out replacing of the printing wheel and ribbon
without any trouble. This eliminates the trouble of the prior art
of detaching the optional components and attaching them again when
the need to replace the printing wheel or ribbon arises, and the
need to look for some place for temporarily depositing the detached
components is also eliminated. The printing sheet already set in
the printing apparatus is not adversely affected by the operation
of opening and closing the front cover and noise silencing cover,
so that the need to reinsert a printing sheet experienced in a
printing apparatus of the prior art can be eliminated. The maximum
width of printing sheets that the printing apparatus can handle
when the optional components are mounted is the same as when no
optional components are mounted. When the printing sheet guide and
page feeder are mounted in combination, the printing sheet guide is
brought to a lying position. However, a space is created between a
ventilating opening formed on a top surface of the upper cover and
a heat sink on a rear surface of the printer body to thereby avoid
a rise in the internal temperature of the printing apparatus that
might otherwise be caused when the ventilating opening is blocked
by the sheets. When no optional components are mounted, the
brackets used for mounting the printing sheet guide and noise
silencing cover can be readily removed, thereby giving a neat
external appearance to the printing apparatus. Thus the need to use
separate printing apparatus suiting the particular optional
component or components is eliminated by the invention which
provides a printing apparatus of high versatility and economical
value.
The blind plates 16 detachably attached to the front cover 2 in
positions inwardly of the hinged portions 2a of the front cover 2
are each formed, as shown in FIG. 16, with resilient claws 16a
adapted to come into engagement with engaging portions formed at
the front cover 2. Thus by pulling the blind plates 16 in the
direction of an arrow, they can be readily detached from the front
cover 2, and they can be attached thereto by pushing in an opposite
direction. When no page feeder is mounted, the blind plates 16 are
left in position as shown in FIG. 3.
When the page feeder 15 is desired to be mounted on the printing
apparatus shown in FIG. 4, the blind covers 16 are detached from
the front cover 2 and the forward ends of the side covers 59 of the
page feeder 15 having the engaging portions 59a are inserted in the
corresponding openings formed at the front cover 2 to bring the
engaging portions 59a into engagement with the shaft of the platen
3. Thus the openings formed by the removal of the blind plates 16
are closed by the side covers 59 of the page feeder 15. In the
present invention, the page feeder 15 can be mounted merely by
bringing the printing sheet guide 11 to a lying position without
requiring its removal.
The front cover 2 of the printing apparatus according to the
invention is constructed as described hereinabove. The blind plates
16 are left in position when no page feeder is mounted, and the
openings formed at the front cover 2 by the removal of the blind
plates 16 can be closed by the side covers 59 of the page feeder
15, thereby avoiding release of noise to outside.
In a printing apparatus, such as the one designated by P in FIG.
17, a carriage 61 supporting a printing section is usually exposed
to view in an opening 63 of a printer body 62. The carriage 61 is
pulled along guides 64 and 65 located parallel to the platen 3 by a
wire 66 trained over pulleys 67 and 68 supported by shafts in a
region defined between the two guides 64 and 65, as shown in FIGS.
17 and 18.
The pulley 68 mounts a gear 69 which is in meshing engagement with
a pinion 71 on a motor 70.
In the aforesaid construction, the wire 66 is an endless wire which
is wound in several turns on the pulley 68 on the drive side, and
the tensioned wire 66 is secured midway to the carriage 61 by a
screw as indicated at 66a.
Mounted between the guides 64 and 65 in a manner to enclose the
pulleys 67 and 68 and support same by shafts while keeping the wire
66 tensioned is a frame 72 which is substantially in the form of a
letter U in an inverted position in cross section and formed at its
top wall with openings 73 in positions corresponding to the
positions of the pulleys 67 and 68 to allow upper end edges of the
pulleys 67 and 68 to stick slightly upwardly out of the openings 73
to enable a top surface of the wire 66 to come into contact with
the carriage 61.
In view of the function of the printing apparatus P to carry out
printing on a sheet supported by the platen 3, the opening 63 in
the apparatus P is left uncovered at all times. This might result
in dust or the hair of operator being deposited on the pulley 67
and 68. When such foreign matter is deposited on the pulleys 67 and
68, the printing positions of the carriage 61 which require high
accuracy and precision would be displaced, causing a change to
occur in spacing. More specifically, if some foreign matter enters
between the wire 66 and the pulleys 67 and 68 maintained in
intimate contact with each other, the wire 66 would be pulled
excessively in either direction, causing a change to occur in the
amount of movement of the carriage 61 which is moved at high speed
for performing printing.
To obviate the aforesaid trouble of the prior art, the invention
provides wire pulley covers which, by preventing the occurrence of
the aforesaid trouble of the prior art, enable printing to be
performed with a high degree of accuracy.
FIGS. 20 and 21 show one embodiment of the wire pulley covers in
accordance with the invention in which the numerals 74 and 75
designate covers for the pulleys 67 and 68 respectively. The covers
74 and 75 which are formed of a synthetic resinous material are
detachably attached to the openings 73 formed in the frame 72
supporting the pulleys 67 and 68 by shafts. The covers 74 and 75
comprise, respectively, cover bodies 74a and 75a large enough to be
located astride the pulleys 67 and 68 sticking upwardly out of the
frame and the wire 66 trained over the pulleys 67 and 68. The
covers 74 and 75 each include engaging claws 76 and 77 attached to
the cover body 74a, 75a at opposite ends for positioning the cover
body 64a, 75a in an opening 73 formed in the frame 72.
As shown in FIG. 22, the engaging claws 76 are in engagement with
an edge portion 73a of the frame 72 defining the opening 73, and
the engaging claws in engagement with an edge portion of a frame 78
defining an opening 68a. Slits 79 are formed along the engaging
claw 77 to allow the claw to resiliently move rearwardly.
Thus the covers 74 and 75 can be attached to the frame 72 to close
the openings 73 in positions near corners of the frames 72 and
78.
The engaging claws 76 of the covers 74 and 75 each have a width
which is commensurate with the inner dimension of the frame 72, and
the engaging claw 77 has a downwardly extending portion 80 which is
commensurate with the frame 72 in dimension, to avoid transverse
displacement of the covers 74 and 75 following their attaching to
the frame 72 to close the openings 73 therein to protect the
pulleys 67 and 68 from dust and other foreign matter.
In the embodiment shown in the drawings, the covers 74 and 75 are
slightly distinct from each other in shape. However, the invention
is not limited to this specific difference in the shape of the
covers 74 and 76 and they may be of the same shape and each may be
symmetrical on the right and left. When this symmetrical
construction is adopted, the carriage 61 should, of course, be
shaped such, by taking into consideration the structural
relationship of the elements of the printing section, that the
carriage 61 is kept from contacting the covers 74 and 75.
By providing the covers 74 and 75 of the aforesaid construction for
the wire pulleys 67 and 68, it is possible to readily set in
positions above the wire pulleys 67 and 68 the covers 74 and 75 so
as to protect the latter from dust to enable them to perform their
functions satisfactorily.
The covers 74 and 75 are formed with the engaging claws 76 and 77
enabling them to be readily attached and detached from the cover 72
of the wire 66. This arrangement allows the covers 74 and 75 to be
readily removed when it is desired to inspect the interior of the
printing apparatus or effect adjustments of the elements of the
printing section.
An additional advantage of the covers 74 and 75 is that they can be
set in place in the printing apparatus by utilizing the openings 73
formed in the frame 72 for the wire 66, without requiring to
provide a special mounting structure at the printer body. This
eliminates a complex working on the printer body and is conducive
to reduced cost.
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